1. Field of the Invention
The present application relates to an image stabilizer for minimizing an influence of disturbances, such as hand-shake, and provides a frame coupling structure with improved manufacturability.
2. Description of the Prior Art
In general, an image stabilizer is used in an electronic apparatus capable of capturing an image, such as a camera, and compensates for movement of the electronic apparatus while capturing an image, which may be due to hand-shake, external vibration, or shock. Basically, the image stabilizer moves an imaging unit, e.g., a Charge-Coupled Device (CCD) or a Complementary Metal-Oxide-Semiconductor (CMOS) sensor, or an optical lens formed on the front of the imaging unit in the direction of pitch/yaw.
Conventionally, a method of operating a compensation lens using an actuator including a rotor and stator with a compensation apparatus has been used to compensate for any displacement generated due to external vibration. Apparatuses utilizing this type of method include a shaft support apparatus, a ball support apparatus, and a suspension wire/spring apparatus.
The shaft support apparatus is generally designed as a two-component structure for moving a compensation lens or an imaging unit, and thus, sensitivity of the compensation may decrease as moving mass increases, and manufacturability may also worsen due to the complicated structure.
The ball support apparatus is also generally designed as a two-component structure, and therefore, the ball support apparatus shares the same problem of decreased compensation sensitivity due to increasing moving mass and degrading manufacturability, although the ball support apparatus may have an advantage in controlling the degree of rotation.
In the suspension wire/spring apparatus, the shape of a supporting material, i.e., a suspension wire or spring, may change while moving mass changes due to external disturbances. Further, energy absorption caused by the change of the shape may decrease in the compensation sensitivity of the image stabilizer.
Additionally, in the suspension wire/spring support apparatus, the degree of rotation of a light axis is not controlled, causing a further decrease in compensation sensitivity, when compared to the shaft support apparatus and the ball support apparatus.
Equation (1) represents the compensation sensitivity of an image stabilizer in the shaft support apparatus and the ball support apparatus, and Equation (2) represents the compensation sensitivity of an image stabilizer in the suspension wire/spring method.
                    K        =                              F            extern                                Δ            ⁢                                                  ⁢            x                                              (        1        )            
In Equation (1) K represents the compensation sensitivity, Fextern represents an external driving force, and Δx represents displacement of driving direction.
                    K        =                                            F              extern                        -                          F              stiffness                                            Δ            ⁢                                                  ⁢            x                                              (        2        )            
In Equation (2), K represents the compensation sensitivity, Fextern represents an external driving force, Fstiffness represents a force by suspension wire/spring, and Δx represents a displacement of driving direction.